What is an i-model, and why can't I modify it?
An i-model is a self describing file format.
There are several benefits to using an i-model:
1 When viewing an i-model, you do not need to have the additional applications in order to view attributes contained within the i-model.2. In many cases the i-model is optimized for better performance when opening and viewing the filePublishing a file to an i-model file format can only be published as read-only. Keep in mind that an i-model is to be used for information exchange not modification aspects.
http://communities.bentley.com/products/w/products__wiki/i-model-faq.aspx
Castellano, Français